Whenever a new update appears,it always seems to bring either major or minor improvements to known issues with previous versions, address some deficiencies found in the same or to prepare for developments that are to come. With this the iOS 9.2 for the iPad Pro, apple fixes the blackout issue.
With iOS 9.2, Apple added a new form, adding to the previous avoid possible problems that may arise for some users newcomer iPad Pro and could cause the device to cease to be usable after being charged, You need to reboot again to get everything back to normal.
To get back to using your iPad Pro, force restart it by pressing and holding both the Sleep/Wake and Home buttons for at least ten seconds, until you see the Apple logo.
Updating your iPad Pro to iOS 9.2 or later might prevent this issue from occurring in the future.
One solution, as noted, thinking more about the future than the present, even when the iPad Pro was released, and appeared a group of users who complained about this ruling after loading the tablet. The ruling affected both the 32GB model and the 128GB and all versions of network connectivity, always using iOS 9.1 firmware as the last common denominator in the situation.
Apple already became aware of the matter in one of the documents supporting its website, reassuring those affected to ensure that they were already working on a way to solve the problem as quickly as possible, something that seems to have met with iOS 9.2 .(Source: Apple)